The following commit has been merged into the x86/entry branch of tip: Commit-ID: 3660da2d124813bed342e25b39df0251cbe2ac4f Gitweb: https://git.kernel.org/tip/3660da2d124813bed342e25b39df0251cbe2ac4f Author: Thomas Gleixner <t...@linutronix.de> AuthorDate: Thu, 26 Mar 2020 16:56:20 +01:00 Committer: Thomas Gleixner <t...@linutronix.de> CommitterDate: Tue, 19 May 2020 16:03:56 +02:00
x86/entry/64: Provide sane error entry/exit For gradual conversion provide a macro parameter and the required code which allows to handle instrumentation and interrupt flags tracking in C. Signed-off-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.char...@oracle.com> Acked-by: Peter Zijlstra <pet...@infradead.org> Acked-by: Andy Lutomirski <l...@kernel.org> Link: https://lkml.kernel.org/r/20200505134904.058904...@linutronix.de --- arch/x86/entry/entry_64.S | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 01bfe7f..96ad26f 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -499,8 +499,9 @@ SYM_CODE_END(spurious_entries_start) * @vector: Vector number * @cfunc: C function to be called * @has_error_code: Hardware pushed error code on stack + * @sane: Sane variant which handles irq tracing, context tracking in C */ -.macro idtentry_body vector cfunc has_error_code:req +.macro idtentry_body vector cfunc has_error_code:req sane=0 call error_entry UNWIND_HINT_REGS @@ -514,6 +515,7 @@ SYM_CODE_END(spurious_entries_start) GET_CR2_INTO(%r12); .endif + .if \sane == 0 TRACE_IRQS_OFF #ifdef CONFIG_CONTEXT_TRACKING @@ -522,6 +524,7 @@ SYM_CODE_END(spurious_entries_start) CALL_enter_from_user_mode .Lfrom_kernel_no_ctxt_tracking_\@: #endif + .endif movq %rsp, %rdi /* pt_regs pointer into 1st argument*/ @@ -538,7 +541,11 @@ SYM_CODE_END(spurious_entries_start) call \cfunc + .if \sane == 0 jmp error_exit + .else + jmp error_return + .endif .endm /** @@ -547,11 +554,12 @@ SYM_CODE_END(spurious_entries_start) * @asmsym: ASM symbol for the entry point * @cfunc: C function to be called * @has_error_code: Hardware pushed error code on stack + * @sane: Sane variant which handles irq tracing, context tracking in C * * The macro emits code to set up the kernel context for straight forward * and simple IDT entries. No IST stack, no paranoid entry checks. */ -.macro idtentry vector asmsym cfunc has_error_code:req +.macro idtentry vector asmsym cfunc has_error_code:req sane=0 SYM_CODE_START(\asmsym) UNWIND_HINT_IRET_REGS offset=\has_error_code*8 ASM_CLAC @@ -574,7 +582,7 @@ SYM_CODE_START(\asmsym) .Lfrom_usermode_no_gap_\@: .endif - idtentry_body \vector \cfunc \has_error_code + idtentry_body \vector \cfunc \has_error_code \sane _ASM_NOKPROBE(\asmsym) SYM_CODE_END(\asmsym) @@ -1403,6 +1411,14 @@ SYM_CODE_START_LOCAL(error_exit) jmp .Lretint_user SYM_CODE_END(error_exit) +SYM_CODE_START_LOCAL(error_return) + UNWIND_HINT_REGS + DEBUG_ENTRY_ASSERT_IRQS_OFF + testb $3, CS(%rsp) + jz restore_regs_and_return_to_kernel + jmp swapgs_restore_regs_and_return_to_usermode +SYM_CODE_END(error_return) + /* * Runs on exception stack. Xen PV does not go through this path at all, * so we can use real assembly here.
